Attachment for vapor-lamps.



A. DBMPSTER.

ATTACHMENT FOR VAPOR LAMPS.

APPLICATION FILED NOV. 9, 1905. RENEWED APR. 4, 1908.

1,006,729, Patented 0'01. 24, 1911.

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W/Z'nesses; V hue/war Aexa d Uem zi'e By {W Atty. v

A. DEMPSTER. ATTACHMENT FOR VAPOR LAMPS. APPLICATION FILED NOV. 9, 1905. REIIEWBD APR. 4, 1908.

1,006,729. Patented 001:. 24, 1911.

2 SHEBTSSHEET 2.

W/Zfnesses:

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' UNITED STATES PATENT O FIC A IZIIEIXAIIDE IBI lllilllllfifilfl-IR. 0F SCHENECTADY,- NEW YORK. ASSIGNOR '10 GENERAL ELECT-RIG COMPANY A CORPQBATIONOF NEW You.

ATTACBMENT FOR VAPOR-LAMPS.

To all whomit may emcam: 7

Be it known that I, ALEXANDER DEMPSTER, a subject of the Kin of Great Britain, re siding at Schenecta y, county of Schenectady, State ofNew York, have invented certain new and useful Improvements in At tachments for Vapor Lamps, of which the following is a specification.

This invention relates to an of vapor lamps whereby, the novel features of my improved form of cut-in device are utilized to advantage.

While my improved cut-in device may be used in connection withvarious'forms of translatirfg devices, itpossesses certain features which make it of special value when used in conjunction with vapor apparatus, such as mercury vapor'lam s. v The details of my inventlon will be bette understood by reference to the following description taken in connection with the drawing forming part of this specification.

Figure 1 is a diagrammatic representation of a series circuit supplying current to three mercury lamps, each of which is provided with a cut-in device of my improved form; Fig. 2 is an elevation partly in section of one modification of my improved cut-in -device; Fig. 3 is a plan view of the same;

mercury and arranged to'make contact with the lower end of filament 7 Plungers of thistype are well known to persons skilledin the art and are shown for instance in United States Patent #850,270, Steinmetz,

April 6, 1907. Surrounding the mercury cathode is a solenoid 9 so disposed that when energized by current it will draw down the mercury plunger 8 in the manner and for the purpose hereinafter described. When potential is impressed on the lamp, current will flowfrom anode 5 through filament 7 Speciflcatioaof Letters Patent. Application filed. Houmher 8, 1805; Serial 8o. 286,514. Renewed improved form of cut-1n devicefor lamps andsimllar apparatus and to an lmproved arrangement Arril4, 1908, Serial no. 425.1

and plunger 8,1:0' themercury cathode 6, and I then through solenoid 9 back to the source Patented Oct, 24!, 1911.

This current through the solenoid" draws. I

' down plunger 8 until it breaks contact with filament 7, thereby producing a spark or are at the end of the filament. This initial spark or are starts thelamp into operation as will be readily understood by rsons skilled in the art. The filament 7 lsf'ordi-i' narily of such high resistance that when-the tube is operating'under normal conditions very little of-the current passing through the tube flows through the filament; therefore, it follows. that when several of these lamps are connected in series the resistance of the cir-.

cuit before the lamps start is much higher than. the normal running vresistance of the circuit. .It has been rounds that when a brush generator is used to energize such a circuit difliculty is sometimes experienced in making the generator buildup to normal current because of this initial high resist ance. Withmy improved form of cutin device arranged as shownin Fig. 1, each of the lamps is short-circuited at startingso that the initial resistance of the circuit is considerably lower-than the normal operating Another difficulty that has been encountered in operating several va or lamps in series arises from the disturbm action ofresistance; consequently no difiiculty is experienced'in starting up the generator.

; one lamp on another during t e starting operation; due no doubttothe considerable variation in resistance when the lamps start or fail to start on the initial current. I

'therefore, find it desirable to provide means for starting one lamp after another-instead of allowing the lamps to start simultaneously the instant pressure is impressed on the 7 distribution circuit: The means for efiecting this result are hereinafter described,

When using lamps of the type above described there is a certain inertia of the movable parts of the lamp, so that an a preciable time elapses between the first ow of' current through the filament and normalfiow through the mercury vapor of the lamp. Because of. this I find it desirable in starting to bring 'up the pressure across each lamp gradually so that the moving parts may have suflicient'time to operate to be t advantage.

Brie form of cut-in device which I have found to meet the above recited conditions is shown in Fig. 1 as comprising a solenoid 10, an armature l2 therefor carrying a dash pot 13 and provided at its lower end with a stop 14 capable of engagement with the 1 lower surface of the contact disk 15 of carbon which at starting rests on two carbon rods 16 and 17, and thereby shunts the lamp 1. The other lamps of the circuit are Similarly equipped except that the stops 18 and 19 of the cut-in devices 20 and 21 are set at different distances below their corresponding disks,so that the three disks will not be lifted simultaneously. This gives a different time constant for each lamp. If desired a self-reducing reslstance 22 may be connected directly across the lamp to act as'a safety deviceand cut'thelamp permanently out of circuit in case of emergency.

The details of ,my' device are shown in Fig. 2. A water proof case 23 of sheet steel or other suitable material is provided with a supporting eye 24, and a cross bar carrying 1nsulators .2 5 and 26 for convenience in connecting theilamp to a commercial circuit. -A solenoid 27 is suspended from the top of the sheet iron casing 23 and is pro.- vided with a movablearmature 28, the upperend of which'fits snugly within a brass sleeve 29, and acts as a dash pot when the armature is drawn upward into the coil. A suitable vent 30 is provided in the plunger of the dash pot.

mounted a thumb screw 32, a lead grid 33 and a carbon bushing 34. When the electromagnet is unexcited the lower end of rod 31 rests on'a fiber post 35. When current is admitted to the electromagnet or solenoid 27 the diskis lifted anarc is drawn armature 28 is drawn up, thus causing an engagement of the web 33 with the lower surface of the carbon disk 36,'thereby-lifting the disk aiiayfrom the two carbon rods and 38. These carbon rods correspond to the contacts 16 and 17 of Fig. 1 and together -with disk 36 form a low resistance shunt When.

path around the lamp before starting.

[0111 each of the carbon rods so that thel'amp is then shunted by a'circuit containing two carbon arcs in series. The upward movement of armature 28 and" the supported disk' 36 is' relatively slowowing to the retarding .ac-

tionof the dash these. carbon arcsincreasesi'gradually." .This.

. voltage across the mercury lam, and allows-ample time for, movement 0 theplunger 28' or other" starting mechanism.

pot, so that thexlengthiof gives a gradual increase 0 Armature 28 carries at- .its lower end a threaded rod 31 on which is distance of travel of-the armature.

leakage inthe dash .pot soon equalizesthe adjustment may be efiecte d by raising orf lowering the thumb screw 32v to increase or decrease the distance through which the armature must travel before the carbon disk I begins to lift. As shown in Figs. 2 and-3 the carbon rods 37 and 38 are rigidly clamped to the upwardly bent ends of brass plates 39 and 40. Theseplate s are connected directly *across the mercury lamp by means of conductors 41v and 42. The lamp itself may be supported below the cut-in by means of a hook 43, and may be connected to the series circuit by conductors 44 and 45. A

magnetite or other self-reducing resistance 46 is connected directly across the lamp and operates to short-circuit the lamp and permanently cut it out-of circuit case-of, emergency. If for any reason the arcs between themovable disk'and the contact rods are drawn. out. and continue to burn, as might occur in case of a defect in the apparatus, the heating action of the-arcs melts Off the arms of the lead grid 33 and permits. 4

the disk 36 to drop back on the contact rods and thus short-circuit the lamp. Four brass guide rods 47,- 48, 49 and 50 insure a proper seatin of this disk on the topyofthe rods when it :fallsb: V i Fig. 6 shows a modified form comprising two electromagnets 51 and 52 connected in series and operable on a U sh'aped' armdture 53 which carries a dash pot cylinder 54, and

across bar :55 of insulating material. This cross bar is provided with holes in which fit two brass sleeves 56 and 57. Carbon rods 58.

and 59 are rigidly clamped in these brass sleeves and project a short distance below the insulating bar. Within the dash pot 54 fits-a plunger 60' rigidly secured to the rod 61- onwhich is a carbon disk 62. A fiberstop 63 serves to limit the downward mo-- tien of the dash pot plunger and its carbon d1sk.. When the apparatus is in the starting positionthe two carbon rods 58 and 59 g'eston the carbondisk 62, and-thus short-circuit the lamp whichv is oonnectedtoconductors 64' and 65, but when? current is passed through the series distribution circuit the solenoids 51 and '52lifa're energized and the armature and :itsfattaiihed dash'pot'c linder 54. are drawn-upward. This ten separate the ,carbonflrbds'fromthe' [carbon disk, but;- t-he suctionofthe'dash pot draws the disk upward With'the; rods so that the- :upward Lmoyement' oil-the; armature does not start-the carbon'aifcs, 01113 lifts the rods 1 arid disk to a distaiieecorrespondin tofthe pressure on the two sides ofthe dashpot plunger and the carbon disk then sinks slowlyaway- ?m theEriods an'd'thus draws two carbon rcs to increase the voltage across the mercu lamp. The rate of travel of the carbon dis is dependent on the leak:

e'slow'.

age or adjustment of the dash pot so that different dash pots ,may be arranged with difi'erent time constants. The brass sleeves 56 and 57 furnish another means of adjustment, for by-changing the setting on the carbon rods the collars can be so adjusted that when the armature is in its lowest position, with the carbon rods seated on the carbon disk, the shoulders on the brass colward with the armature.

What I claim as new and desire to secure by Letters Patent of the United States, is,- 1. The combination. of a vapor lamp, a conducting path in shunt with said lamp, and means for producing a plurality of sustained arcs in said shunt-path to gradually increase the voltage on said vapor. electric apparatus. .7 v

2. The combination ofa' vapor lamp, arcing contacts connected to the terminals of said lamp, a contact-plate for connecting said contacts, and automatic means for gradually moving said plate from said contacts to start said lamp. i

3. The combination of a vapor lamp, arcin contacts connected to the terminals of said lamp, a conducting plate for connecting tarding device operatively connected to said conducting plate.

p 4, The combination of a vapor lamp, means for shunting said. lamp with a plurality of sustained arcs and for gradually increasing the length of said arcs, and a retarding means to govern the speed of said increase in length.

5. The combination of a seriesconsumption circuit, a plurality of vapor lamps connected thereto, means for shunting each of said lamps wit-ha plurality of sustained arcs, means-for increasing the voltagedrop across said -arcs to start said lamps, and means for preventing the simultaneous starting of said lamps.

6. A cut-in device comprising an electromagnet, a' movable armature therefor, a plate carried by said armature, arcing contacts initially bridged by said plate, and a retarding device for regulating the rate of movement of said armature.

7. A cut-in device comprisi an electromagnet, a movable armature t erefor, contacts to be separated by movement of said armature to form a sustained arc, and an I adjustable connection between said armature and meet sa1d contacts to permit a vanation of the length of travel of said 'arma-' tureb'efore separating said contacts thereby varying the time interval elapsing between the energizing of said eleptromagnet and theformation of said sustained are.

8. The combinationof avapor lamp, a

conducting path in shunt with said lamp, means for increasing the resistance of sa1d shunt path to start the lamp, and fusible means coacting with said means for efiectin a decrease in the resistance of said path i the vapor lamp fails to start.

9. A cut-in device. having a plurality of rods, a plate initially brid lng said rods, an

"armature for lifting said p ate, and a fusible connection between'said armature and plate. In witness whereof, I have hereunto set my. hand this 8th day of November, 1905.

I ALEXANDER DEMPSTER.

Witnesses: i

BENJAMIN B. HULL, MARGARET E. WooLLmr. 

